Two-Year Clinical Outcome of MitraClip Transcatheter Edge-to-Edge Repair from the J-MITRA Registry Data

Background: The introduction of transcatheter edge-to-edge repair for moderate-to-severe or severe mitral regurgitation (MR) utilizing the MitraClip system became reimbursed and clinically accessible in Japan in April 2018. This study presents the 2-year clinical outcomes of all consecutively treated patients who underwent MitraClip implantation in Japan and were prospectively enrolled in the Japanese Circulation Society-oriented J-MITRA registry. Methods and Results: Analysis encompassed 2,739 consecutive patients enrolled in the J-MITRA registry with informed consent (mean age: 78.3}9.6 years, 1,550 males, STS risk score 11.7}8.9), comprising 1,999 cases of functional MR, 644 of degenerative MR and 96 in a mixed group (DMR and FMR). The acute procedure success rate was 88.9%. After MitraClip implantation, >80% exhibited an MR grade ≤2+ and the trend was sustained over the 2 years. Within this observation period, the mortality rate was 19.3% and the rate of heart failure readmissions was 20.6%. The primary composite endpoint, inclusive of cardiovascular death and heart failure readmission, was significantly higher in patients with functional MR than in with degenerative MR (32.0% vs. 17.5%, P<0.001). Conclusions: The 2-year clinical outcomes after MitraClip implantation were deduced from comprehensive data within an all-Japan registry.